BRYAN SUPRAN - 02 Mar 2026 Form 4 Insider Report for ALNYLAM PHARMACEUTICALS, INC. (ALNY)

Role: EVP, CLO and Secretary
Signature: By: Brett Budzinski, Attorney-in-Fact For: Bryan A. Supran
Issuer symbol: ALNY
Transactions as of: 02 Mar 2026
Net transactions value: $0
Form type: 4
Filing time: 04 Mar 2026, 19:29:40 UTC
Previous filing: 03 Oct 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
SUPRAN BRYAN	EVP, CLO and Secretary	675 WEST KENDALL STREET, HENRI A. TERMEER SQUARE, CAMBRIDGE	By: Brett Budzinski, Attorney-in-Fact For: Bryan A. Supran	04 Mar 2026	0001511797

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	ALNY	Common Stock	Award		+1,539	+12%	$0.000000^*	14,565	02 Mar 2026	Direct	F1

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	ALNY	Stock Option (right to buy)	Award		+3,381		$0.000000^*	3,381	02 Mar 2026	Common Stock	3,381	$325.07	Direct	F2

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	These shares are represented by restricted stock units (RSUs) granted under the Second Amended and Restated 2018 Stock Incentive Plan. Each RSU represents a contingent right to receive one share of common stock. The RSUs will vest over a three-year period, with one third vesting on each of the first, second and third anniversaries of the grant date, subject to the Reporting Persons continuous service with the Issuer as of each such vesting date.
F2	The stock option vests as to 25% of the shares on the first anniversary of the grant date and the remaining shares vest in equal installments at the end of each successive three-month period thereafter until the fourth anniversary of the grant date, subject to the Reporting Persons continuous service with the Issuer as of each such vesting date.

Content

These shares are represented by restricted stock units (RSUs) granted under the Second Amended and Restated 2018 Stock Incentive Plan. Each RSU represents a contingent right to receive one share of common stock. The RSUs will vest over a three-year period, with one third vesting on each of the first, second and third anniversaries of the grant date, subject to the Reporting Persons continuous service with the Issuer as of each such vesting date.

The stock option vests as to 25% of the shares on the first anniversary of the grant date and the remaining shares vest in equal installments at the end of each successive three-month period thereafter until the fourth anniversary of the grant date, subject to the Reporting Persons continuous service with the Issuer as of each such vesting date.